One-time-use camera with fracture line of weakness non-coincident to pivot axis of film door

ABSTRACT

An opaque rear cover part for a one-time-use camera comprising a door cover portion and a remaining cover portion arranged to permit the door cover portion to be pivoted open relative to the remaining cover portion about a pivot axis, and a fracture line of weakness formed between the door cover portion and the remaining cover portion to create a break along the fracture line of weakness which permits the door cover portion to be separated from the remaining cover portion when the door cover portion is pivoted open, is characterized in that the fracture line of weakness is entirely not coincident with the pivot axis and is angled with respect to the pivot axis in order to effect a shearing stress in addition to a bending stress at the fracture line of weakness which causes the door cover portion to separate from the remaining cover portion when the door cover portion is pivoted open.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application commonlyassigned copending Ser. No. 09/234,603 entitled ONE-TIME-USE CAMERA WITHFRACTURE LINE OF WEAKNESS NON-COINCIDENT TO PIVOT AXIS OF FILM DOOR andfiled Jan. 21, 1999 in the names of Randy E. Horning and Dennis J.O'Dea.

Further reference is made to commonly assigned application Ser. No.09/234,763 entitled ONE-TIME-USE CAMERA WITH ANTI-BACKUP PAWL FOR FILMWINDER INCAPACITATED WHEN FILM DOOR OPENED TO REMOVE FILM CARTRIDGE andfiled Jan. 21, 1999 in the names of Randy E. Homing, Raymond P. Chapman& James G. Rydelek, now abandoned.

FIELD OF THE INVENTION

The invention relates generally to the field of photography, and inparticular to one-time-use cameras. More specifically, the inventionrelates to a one-time-use camera that is incapacitated to prevent itsreuse when a film door is opened to remove a film cartridge.

BACKGROUND OF THE INVENTION

Film and cameras that are all in one, commonly referred to as single-useor one-time-use cameras, have become well known. The one-time-use camerais a simple point-and-shoot type comprising a plastic main body partwhich supports a conventional film cartridge in a cartridge receivingchamber, a film take-up spool in a film supply chamber, a fixed-focustaking lens, a film metering mechanism with a rotatably supportedmetering sprocket that engages the filmstrip, a manually rotatable filmwinding thumbwheel rotatably engaged with a film spool inside the filmcartridge, a single-blade shutter, a manually depressible shutterrelease button, a rotatable frame counter for indicating the number ofexposures remaining to be made on the filmstrip, a direct see-throughviewfinder, and in some models an electronic flash. A pair of plasticfront and rear cover parts house the main body part between them tocomplete the camera unit. The rear cover part connects to the main bodypart and/or to the front cover part to make the main body partlight-tight. A decorative cardboard outer box or label at leastpartially covers the camera unit and has respective openings for thetaking lens, etc.

After each picture is taken with the one-time-use camera, thephotographer manually rotates the thumbwheel in a film winding directionto similarly rotate the film spool inside the film cartridge. This windsan exposed section of the filmstrip into the film cartridge. Therewinding movement of the filmstrip the equivalent of slightly more thanone frame width rotates the metering sprocket in engagement with thefilmstrip to decrement the frame counter to its next lower-numberedsetting and to pivot a metering lever into engagement with thethumbwheel in order to prevent further manual rotation of thethumbwheel. Manually depressing the shutter release button to takeanother picture pivots the metering lever out of engagement with thethumbwheel to permit renewed rotation of the thumbwheel. When themaximum number of exposures available on the filmstrip have been made,and the filmstrip is completely wound into the film cartridge, theone-time-use camera is given to a photofinisher who tears the outer boxoff the camera unit, separates the rear cover part from the main bodypart, and removes the film cartridge with the exposed filmstrip from thecartridge receiving chamber. Then, he removes the exposed filmstrip fromthe film cartridge to develop the negatives and make prints for thecustomer. At least some of the used camera parts may be recycled, i.e.reused, to remanufacture the camera.

Prior Art Problem

There is a problem in the recycling, i.e. reuse, of used camera parts,in that the reused parts may become worn or damaged. Thus, it has beensuggested that any worn or damaged parts be purposely fractured torender them visibly different during disassembly of the one-time-usecamera to retrieve the exposed film. This allows the worn or damagedparts to be readily identified to be discarded, and prevents them frombeing erroneously reused.

A possible solution to the problem of erroneously reused parts isdisclosed in prior art U.S. Pat. No. 5,761,542 issued Jun. 2, 1998. Inthe patent, a fracture line of weakness or v-shaped groove divides adoor cover portion of the rear cover part and a remaining cover portionof the rear cover part along a pivot axis of the door cover portion. Thedoor cover portion is to be pivoted open relative to the remaining coverportion to remove the film cartridge from the cartridge receivingchamber. An anti-backup pawl is located in a slot that longitudinallyextends between the door cover portion and the remaining cover portion.A fixed end of the anti-backup pawl is connected to the remaining coverportion at the fracture line of weakness and to the door cover portionadjacent the fracture line of weakness. A free end of the anti-backuppawl engages the thumbwheel. When the door cover portion is pivoted openrelative to the remaining cover portion, a break is created along thefracture line of weakness which permits the door cover portion to beseparated from the remaining cover portion in order to prevent the rearcover part from being reused. The anti-backup pawl is moved with thedoor cover portion to break the fixed end of the anti-backup pawl at thefracture line of weakness.

Since in the patent the fracture line of weakness is coincident with thepivot axis of the door cover portion, pivoting the door cover portionopen subjects it only to bending (not shearing) stress. Thus, the doorcover portion is not very easily separated from the remaining coverportion.

The Cross-Referenced Application

The cross-referenced application discloses an opaque rear cover part fora one-time-use camera comprising a door cover portion and a remainingcover portion that are connected to permit the door cover portion to bepivoted open relative to the remaining cover portion, a slot havingopposite ends that longitudinally extends between the door cover portionand the remaining cover portion, and an anti-backup pawl supported inthe slot for engaging a film winding thumbwheel that is to be located inthe slot. The anti-backup pawl has respective connections with the doorcover portion and the remaining cover portion that project between theopposite ends of the slot from the anti-backup pawl to the door coverportion and the remaining cover portion to support the anti-backup pawlin the slot. One of the connections is constructed to be torn apart whenthe door cover portion is pivoted open relative to the remaining coverportion in order that the anti-backup pawl will no longer be connectedto the door cover portion or the remaining cover portion.

SUMMARY OF THE INVENTION

An opaque rear cover part for a one-time-use camera comprising a doorcover portion and a remaining cover portion arranged to permit the doorcover portion to be pivoted open relative to the remaining cover portionabout a pivot axis, and a fracture line of weakness formed between thedoor cover portion and the remaining cover portion to create a breakalong the fracture line of weakness which permits the door cover portionto be separated from the remaining cover portion when the door coverportion is pivoted open, is characterized in that:

the fracture line of weakness is entirely not coincident with the pivotaxis and is angled with respect to the pivot axis in order to effect ashearing stress in addition to a bending stress at the fracture line ofweakness which causes the door cover portion to separate from theremaining cover portion when the door cover portion is pivoted open.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exterior rear elevation view of a one-time-use camera;

FIG. 2 is a blow-up of a portion of FIG. 1;

FIG. 3 is an interior elevation view of a rear cover part of theone-time-use camera;

FIG. 4 is a blow-up of a portion of FIG. 1;

FIG. 5 is an exterior rear elevation view of the one-time-use camera,showing a door cover portion of the rear cover part pivoted openrelative to a remaining cover portion of the rear cover part;

FIG. 6 is an interior elevation view of the rear cover part, showing thedoor cover portion pivoted open relative to the remaining cover portionas in FIG. 5;

FIG. 7 is an exterior rear elevation view of the one-time-use camera,showing the door cover portion separated from the remaining coverportion; and

FIG. 8 is an interior elevation view of the rear cover part, showing thedoor cover portion separated from the remaining cover portion as in FIG.7.

DETAILED DESCRIPTION OF THE INVENTION

The invention is disclosed as being embodied preferably in aone-time-use camera. Because the features of a one-time-use camera aregenerally known, the description which follows is directed in particularonly to those elements forming part of or cooperating directly with thedisclosed embodiment. It is to be understood, however, that otherelements may take various forms known to a person of ordinary skill inthe art.

Referring now to the drawings, FIGS. 1-8 show a one-time-use camera 10which includes a plastic opaque main body part 12 and a pair of plasticopaque front and rear cover parts 14 and 16 which house the main bodypart between them.

As is known, the main body part 12 has a rearwardly open cartridgereceiving chamber 18 for a film cartridge 20 and a rearwardly open filmsupply chamber (not shown) for an unexposed film roll. See FIG. 7. Abackframe opening (not shown) is located between the cartridge receivingchamber 18 and the film supply chamber for exposing successive imagingsections of a filmstrip initially stored on the unexposed film roll.

The rear cover part 16 has a door cover portion 22 and a remaining coverportion 24. A pair of lead-in notches 26 and 28 in the rear coverportion 16 allow the door cover portion 22 to be pivoted open relativeto the remaining cover portion 24 about a pivot axis 30, from thecartridge receiving chamber 18. See FIGS. 1, 3, 5 and 6. The door coverportion 22 is pivoted open to permit the film cartridge 20 to be removedfrom the cartridge receiving chamber 18.

A slot 32 in the rear cover part 16 has opposite ends 34 and 36 andlongitudinally extends between the door cover portion 22 and theremaining cover portion 24. See FIGS. 1 and 2. A film winding thumbwheel38, rotatably supported on the main body part 12, protrudes outwardlyfrom the slot 32 and has a depending coaxial stem (not shown) in coaxialengagement with one end 40 of a film spool in the film cartridge 20.Manual winding rotation of the film winding thumbwheel 38 clockwise inFIG. 7 similarly rotates the film spool 40 to wind each exposed sectionof the filmstrip into the film cartridge 20.

An anti-backup pawl 42 integrally formed with the rear cover part 16 hasa pair of free ends 44 and 46 and respective thin flexible connections48 and 50 to the door cover portion 22 and the remaining cover portion24 that project in opposite directions between the free ends to supportthe anti-backup pawl in the slot 32. The free ends 44 and 46 of theanti-backup pawl 42 are each positioned in the slot 32 spaced from theopposite ends 34 and 36 of the slot. One of the free ends 44 and 46,i.e. the free end 46, engages the film winding thumbwheel 38 to preventunwinding rotation of the thumbwheel counterclockwise in FIG. 7. Whenthe door cover portion 22 is initially pivoted open as shown in FIGS. 5and 6, the free end 46 of the anti-backup pawl 42 is disengaged from thethumbwheel 38. Then, the connection 48 between the anti-backup pawl 42and the remaining cover portion 24 is broken and torn apart and theconnection 50 between the anti-backup pawl and the door cover portion isbent and twisted in order to incapacitate the anti-backup pawl. Thisoccurs before the door cover portion 22 is opened wide enough to permitthe film cartridge 20 to be removed from the cartridge receiving chamber18. Of course, the connection 50 instead of the connection 48 can betorn apart when the door cover portion 22 is pivoted open.

A fracture line of weakness 52, preferably a v-shaped groove in the rearcover part 16, divides the door cover portion 22 and the remaining coverportion 24. As shown in FIG. 3, the fracture line of weakness 52longitudinally extends almost (but not quite) to the pivot axis 30. Thatis, it has opposite ends 80 and 82 that end very slightly before, i.e.immediately short of, the pivot axis 30, for the opposite ends to benearby (and not touching) pivot axis. The ends 80 and 82 are spaced lessthan a 1/4 inch from the pivot axis 30. The fracture line of weakness 52is entirely not coincident with the pivot axis 30 and is angled withrespect to the pivot axis in order to effect a shearing stress inaddition to a bending stress at the fracture line of weakness when thedoor cover portion 22 is pivoted open. See FIGS. 7 and 8. These stressescause the door cover portion 22 to break and separate completely alongthe fracture line of weakness 52, and to break and separate slightlybeyond the ends 80 and 82 to the pivot axis 30, from the remaining coverportion 24, when the door cover portion is pivoted open. As shown inFIG. 3, the fracture line of weakness 52 extends at an acute angle 54from the pivot axis 30 to a peak 56 which is a maximum distance 58 fromthe pivot axis, and back toward the pivot axis at an acute angle 60, inorder that the break and separation along the fracture line of weakness,and slightly beyond the ends 80 and 82 to the pivot axis 30, begins atthe peak when the door cover portion 22 is pivoted open. This occursbefore the door cover portion 22 is opened wide enough to permit thefilm cartridge 20 to be removed from the cartridge receiving chamber 18.A plurality of strengthening ribs 62 extend across the pivot axis 30 andnot across the fracture line of weakness 52, and a plurality of borderribs 64 extend along opposite sides 66 and 68 of the fracture line ofweakness and not along opposite sides 70 and 72 of the pivot axis, toprevent the break along the fracture line of weakness from alsooccurring along the pivot axis.

The invention has been described with reference to a preferredembodiment. However, it will be appreciated that variations andmodifications can be effected by a person of ordinary skill in the artwithout departing from the scope of the invention.

PARTS LIST

10. one-time-use camera

12. main body part

14. front cover part

16. rear cover part

18. cartridge receiving chamber

20. film cartridge

22. cover door portion

24. remaining cover portion

26. lead-in notch

28. lead-in notch

30. pivot axis

32. slot

34. opposite end

36. opposite end

38. film winding thumbwheel

40. film spool

42. anti-backup pawl

44. free end

46. free end

48. connection

50. connection

52. fracture line of weakness

54. angle

56. peak

58. maximum distance

60. angle

62. strengthening ribs

64. border ribs

66. opposite side

68. opposite side

70. opposite side

72. opposite side

80. opposite end

82. opposite end

What is claimed is:
 1. An opaque rear cover part for a one-time-usecamera comprising a door cover portion and a remaining cover portionarranged to permit said door cover portion to be pivoted open relativeto said remaining cover portion about a pivot axis, and a fracture lineof weakness formed between said door cover portion and said remainingcover portion to create a break along said fracture line of weaknesswhich permits said door cover portion to be separated from saidremaining cover portion when said door cover portion is pivoted open, ischaracterized in that:said fracture line of weakness is entirely notcoincident with the pivot axis and is angled with respect to the pivotaxis in order to effect a shearing stress in addition to a bendingstress at said fracture line of weakness which causes said door coverportion to separate from said remaining cover portion when said doorcover portion is pivoted open.
 2. A one-time-use camera as recited inclaim 1, wherein said fracture line of weakness has a pair of oppositeends that are nearby said pivot axis.
 3. A one-time-use cameracomprising a main body part having a cartridge receiving chamber, a filmcartridge in said chamber, an opaque rear cover part having a door coverportion and a remaining cover portion arranged to permit said door coverportion to be pivoted open from said chamber about a pivot axis, and afracture line of weakness formed between said door cover portion andsaid remaining cover portion to create a break along said fracture lineof weakness which permits said door cover portion to be separated fromsaid remaining cover portion when said door cover portion is pivotedopen, is characterized in that:said fracture line of weakness isentirely not coincident with the pivot axis and is angled with respectto the pivot axis in order to effect a shearing stress in addition to abending stress at said fracture line of weakness which causes said doorcover portion to separate from said remaining cover portion when saiddoor cover portion is pivoted open.
 4. A one-time-use camera as recitedin claim 3, wherein said fracture line of weakness has a pair ofopposite ends that are nearby said pivot axis.